Technical Field
The present invention relates to a lighting apparatus. More particularly, the present invention relates to a lighting apparatus and a lens structure thereof.
Description of Related Art
A typical LED package has a fixed beam angle such as 120 degrees. In order to satisfy optical characteristics of various lighting module, a second lens is employed to cover the LED package to adjust the illumination distribution of the LED.
The LED package includes an LED chip, a reflective cup and a fluorescent material. The fluorescent material and the LED chip are encapsulated in the recess of the reflective cup. Because the LED package emits a light only through its top surface, the shapes of the light incident surface and the light outgoing surface of the second lens are designed only based on the illumination distribution of the top surface of the LED package.
In pace with the manufacturing progress, a fluorescent film is employed to direct cover the LED chip, and in such a configuration, the LED chip is not required to be encapsulated in the reflective cup. However, since the reflective cup is omitted, the lateral surface of the LED chip emits light to the circuit board, and this light will be reflected to the second lens, which causes unduly high brightness above the LED chip.